FR2965871A1 - CORRECTION BAND DISPENSER WITH VARIABLE CLUTCH MECHANISM - Google Patents

Abstract

The invention relates to a clutch mechanism 100 for a belt dispenser, comprising coaxially arranged first and second rotation discs, a pressure wheel 102 and a friction element 104. The first disc defines at least one protrusion 114. The wheel 102 is disposed between the first and second disks and is operatively engaged by the movable protrusion 114 between first and second rotational positions relative to the pressure wheel 102. The friction element 104 is disposed between the pressure wheel 102 and the second disk so that the friction element 104 generates a first frictional force between the pressure wheel 102 and the second disk when the protuberance 114 is in the first rotational position and a second frictional force between the pressure wheel 102 and the second disk when the protuberance 114 is in the second rotational position.

Description

The present invention relates to clutch mechanisms and, more particularly, correction tape dispensers having clutch mechanisms. BACKGROUND OF THE INVENTION Correction tape dispensers can be used to cover errors made on media, such as a sheet of paper, including writing or typing errors. In a common example, a correction tape dispenser comprises a casing within which are disposed a supply reel and a reel or rewind reel. A carrier tape has a first end wrapped around the supply reel and a second end wrapped around a receiving reel. One side of the carrier tape is coated with a corrective coating that is used to cover an error on a carrier. There are known distributors of correction tape having supply and receiving coils which rotate about a common axis, the supply coil being coupled to drive the receiver coil through a control mechanism. 'clutch. An applicator tip having a platform with a leading edge is attached to the housing, the leading edge being outside the housing. The applicator tip contributes to the transfer of the corrective coating of the carrier tape on the paper. The housing can be held by a user's hand during use. Moving from the supply reel to the receiving reel, the carrier tape is directed to the applicator tip, across the platform, around the leading edge and back to the receiving reel. The front edge of the applicator tip creates an acute curvature of the ribbon to help release the corrective coating from the ribbon. The leading edge presses the carrier tape against the surface of a sheet of paper or other carrier to transfer the corrector coating of the carrier tape to the paper to cover an error made thereon and to facilitate correction of the error. As the leading edge is moved over the paper, the carrier tape with a new corrective coating is pulled from the feed reel while the take-up reel is driven to wind up the carrier tape that has passed through the reel. front edge and from which the corrective coating is removed. A continuous right strip of corrective coating is thus affixed to the paper surface until the forward movement of the applicator tip is stopped and the tip is lifted from the paper. With such correction tape dispensers, it is well known that the pulling force required to apply the correction tape to the media increases steadily over the life of the product while the torque required to pull the correction tape out of the supply coil remains substantially constant. The torque is equal to the pulling force multiplied by the radius of the correction tape stored on the feed reel. It can be seen that the radius of the feed reel decreases as the stock of correction tape decreases. Therefore, to maintain a constant torque, the tensile force applied to the correction band must be increased to compensate for the reduction of the band radius. The variable clutch mechanism described advantageously facilitates the correspondence between rotational speeds of the supply reel and the take-up reel throughout the life of a web transfer product, allowing the consumer to have a more user-friendly mechanism for applying a band. More specifically, the variable clutch mechanism automatically adjusts the relative speed at which the take-up reel rotates relative to the supply reel to ensure smooth transfer of the supply reel tape to the carrier tape. is collected by the receiving coil without generating too much or too little voltage of the correction tape and / or carrier tape, thus avoiding operational inconsistencies such as tearing and / or looping. One aspect of the present disclosure relates to a clutch mechanism including a first rotation disk, a second rotation disk, a pressure wheel, and a friction element. The first rotation disc defines at least one protuberance. The second rotation disk is disposed coaxially with the first rotation disk. The pressure wheel is arranged coaxially with and between the first and second rotation discs. The pressure wheel is operatively engaged by the at least one protuberance carried by the first rotation disk. The at least one protrusion is movable between at least a first rotational position and a second rotational position with respect to the pressure wheel. The friction element is disposed between the pressure wheel and the second rotation disk so that the friction element generates a first friction force between the pressure wheel and the second rotation disk when the at least one protuberance is in the first rotational position and a second friction force between the pressure wheel and the second rotation disk when the at least one protrusion is in the second rotational position. Another aspect of the present disclosure relates to a correction tape dispenser comprising a casing, an applicator head carried by the casing, a feed reel, a take-up spool, a pressure wheel, and a friction element. The feed wheel is supported within the housing and adapted to carry a correction tape feed disposed on a carrier tape to be applied to a carrier by the application head. In addition, the feed reel defines at least one protuberance. The receiving coil is supported within the housing and disposed coaxially with the feed wheel to collect the carrier tape after the correction band has been applied to the carrier by the application head. The pressure wheel is arranged coaxially with and between the supply and receiving coils. It is operatively engaged by the at least one protrusion of the feed reel. The at least one protrusion is movable between at least a first rotational position and a second rotational position with respect to the pressure wheel. The friction element is disposed between the pressure wheel and the receiving coil so that the friction element generates a first frictional force between the supply and the receiving coils when the at least one protuberance is in position. the first rotational position and a second frictional force between the supply and the receiving coils when the at least one protuberance is in the second rotational position. Another aspect of the present disclosure relates to a correction tape dispenser comprising a housing, a feed reel, a take-up reel, a carrier tape, a pressure wheel, and an O-ring. The housing carries an application head and a shaft. The feed spool is rotatably supported on the shaft and defining a hump. The receiving coil is rotatably supported on the shaft adjacent to the feed reel. The carrier tape carries a correction tape feed and extends from the feed reel, around the application head, to the receiving reel. The pressure wheel is disposed on the shaft between the supply and the receiving coils and defines a cam surface which is operatively engaged by the bump of the supply reel.

The supply spool is movable relative to the pressure wheel so that the boss can be displaced with respect to the cam surface between at least a first rotational position and a second rotational position. The pressure wheel is movable relative to the supply reel between at least a first axial position when the boss is in the first rotational position and a second axial position when the boss is at the second rotational position. The O-ring is disposed between the pressure wheel and the receiving coil so that the O-ring occupies a first state of compression and generates a first frictional force between the supply and receiving coils when the bump is located. in the first rotational position and the pressure wheel is in the first axial position, and a second compression state generating a second friction force between the supply and the receiving coils when the boss is in the second position of rotation and the pressure wheel is in the second axial position. Fig. 1 is a partial side cross-sectional view of a correction tape dispenser 20 comprising a variable clutch mechanism and constructed according to the principles of the present disclosure; Fig. 2 is an upper partial cross-sectional view of the correction tape dispenser of Fig. 1; Figs. 3A to 3C are partial cross-sectional side views of an embodiment of a variable clutch mechanism incorporated in a correction tape dispenser and constructed according to the principles of the present disclosure; Fig. 4 is a partial cross-sectional side view of another embodiment of a variable clutch mechanism incorporated in a correction tape dispenser and constructed according to the principles of the present disclosure; Fig. 5 is a partial cross-sectional side view of another alternative embodiment of a variable clutch mechanism incorporated in a correction tape dispenser and constructed according to the principles of the present disclosure; Fig. 6 is a partial cross-sectional side view of another alternative embodiment of a variable clutch mechanism incorporated in a correction tape dispenser and constructed according to the principles of the present disclosure; Fig. 7 is a partial cross-sectional side view of another alternative embodiment of a variable clutch mechanism incorporated in a correction tape dispenser and constructed according to the principles of the present disclosure; and Fig. 8 is a schematic representation of an embodiment of a camming driven surface of a pressure wheel which may be incorporated into a variable clutch mechanism constructed in accordance with the principles of the present disclosure. The present disclosure relates to a variable clutch mechanism and a correction tape dispenser including a variable clutch mechanism to assist in ensuring uniform application of the correction band. The variable clutch mechanism described herein is not limited to being used in a correction tape dispenser, and it is conceivable to use it in any other device that can take advantage of its functional aspects, including in particular but not limited to other transfer band mechanisms such as fluorescent "highlighter" tape transfer mechanisms or double-sided tape, for example. The variable clutch mechanism described advantageously reduces the difference in tractive force required to apply the correction band throughout the life of the product, and preferably facilitates the use of substantially the same tensile force for apply the correction (or other) tape to the media throughout the life of the product, making the device easier to use and more consistent over the life of the product. In addition, the variable clutch mechanism automatically adjusts the relative speed at which the take-up reel rotates relative to the supply reel to ensure smooth transfer of the supply reel tape so that the sliver carrier is collected by the receiving coil without generating a voltage too large or too small in the tape correction tape and / or in the carrier tape, which avoids operating irregularities such as tearing and / or looping. Figures 1 and 2 illustrate an embodiment of a correction tape dispenser 10 constructed in accordance with the principles of the present description and including a variable clutch mechanism 100 (shown schematically in Figure 2). In general, the correction tape dispenser 10 comprises a housing 12, a feed reel 14, a rewinding or rewinding reel 16, an application head 18, a correction tape feed 20, and a 22. The housing 12 is generally conventional in that it may comprise a pair of housing shells, for example snapped or otherwise connected to each other to define a cavity which contains the inner workings of the distributor 10. supply and receiving coils 14, 16 of the present embodiment of the correction tape dispenser 10 generally comprise rotational disks, or disc-shaped members, which are arranged coaxially on the shaft 22 for rotational movement. . The application head 18 may resemble any conventional application head attached to the housing 12 and having an application edge 24. The correction tape 20 comprises a length of carrier tape 20a and a web length 20b correction related to the carrier tape 20a. The tape carrier tape 20 extends from the feed reel 14, around the application edge 24 of the application head 18, and to the receiving reel 16. During operation, a user presses the application edge 24 of the application head 18 against a support, such as a piece of paper for example, and moves the correction tape dispenser 10 in a direction substantially opposite to the initial location of the application head 18 The correction band 20b carried by the carrier tape 20a is formulated to adhere to the carrier. Therefore, the previous displacement of the correction tape dispenser 10 applies or generates a pulling force F, which pulls the correction tape strip 20 from the feed reel 14. This movement causes the distribution of the correction band 20b of the housing and finally the application of the correction band so that it separates from the carrier tape 20a and adheres to the support. The carrier tape 20a is then collected on the reception roll 16.

As discussed above, the pulling force F required to extract or unwind the correction band 20a from the feed reel 14 increases steadily over the life of the product. The tensile force F increases because the torque needed to pull the correction tape 20 from the feed reel 14 remains substantially constant and the radius R of the correction tape 20 on the feed reel 14 decreases. A substantially constant torque is maintained so that the correction tape strip 20 can be unwound from the feed reel 14 in a homogeneous manner. Thus, the user of a conventional correction tape dispenser must apply an increasing tensile force F to the correction tape 20 as the tape of the correction tape 20 is fed to the tape reel. 14 feed decreases. The correction tape dispenser 10 of the described embodiment, however, has the variable clutch mechanism 100 to mitigate this disadvantage and to ensure that the user can apply a substantially constant tensile force F for the application of the tape. correction 20b on a support in a coherent manner. Figs. 3A-3C show an embodiment of a variable clutch mechanism 100 constructed according to the principles of the present disclosure and which may be included as a component of the otherwise conventional correction tape dispenser 10 described above in accordance with 1 and 2. The variable clutch mechanism 100 comprises the supply and receiving coils 14, 16 of the preceding correction tape dispenser 10, a pressure wheel 102, and a friction element 104. As such has been illustrated and mentioned above, the supply and receiving coils 14, 16 are arranged coaxially on the shaft 22 of the correction strip dispenser 10 for rotational displacement, and they generally comprise disks or members disc shape. The feed reel 14 retains a stock of the correction tape 20, and the reel 16 retains a used stock of the carrier tape 20a. In the described embodiment of the variable clutch mechanism 100, the feed reel 14 includes an inner surface 106, an outer surface 108, an opening 110, a cylindrical recess 112 and at least one protrusion 114. The receiving reel 16 comprises an inner surface 116, an outer surface 118, a sleeve 120 and an annular recess 123. In the present embodiment, the at least one protuberance 114 on the supply reel 14 includes first and second hemispherical bumps. 115a, 115b disposed in the cylindrical recess 112, but generally any geometric shape providing a contact surface may be used. The first and second bumps 115a, 115b are disposed approximately 180 degrees to each other to facilitate operation of the clutch mechanism 100, as will be described hereinafter. the orientation of the feed reel 14 in Figures 3A and 3C, the second bump 115b is only visible in Figure 3. In alternative embodiments, the feed reel 14 may comprise more or less than two bumps 115a, 115b and the bumps 115a, 115b may have a shape other than a hemispherical shape, as described above, Other relative angular positions of the first and second hemispherical bumps 115a, 115b are also possible. For example, the hemispherical bumps may be arranged at approximately one hundred twenty degrees (120 degrees), ninety degrees (90 degrees), sixty degrees (60 degrees), or forty-five degrees (45 degrees). other, the sleeve 120 the receiving coil 16 may generally comprise two or more partially cylindrical concentric members extending away from the inner surface 116 of the receiving coil 16 to facilitate and maintain assembly of the mechanism 100. More specifically, the sleeve 120 defines a bore 124 rotatably disposed on the shaft 22 and extending through the opening 110 in the feed reel 14. The sleeve 120 further comprises a lock 126 which may include one or more members generally tooth-shaped extending radially outwardly from the sleeve 120 and engaging the outer surface 108 of the supply reel 14. The lock 126 thus configured serves to prevent the supply and 14, 16 do not deviate from their intended location on the shaft 22. During assembly, the two or more cylindrical members or more of the sleeve 120 may be are adapted to compress elastically in the radial direction so that the latch 126 can pass through the opening 110 in the feed reel 14 before returning to their natural state, which is shown in Figure 3A, for example.

With reference to FIG. 3A, the pressure wheel 102 of the present embodiment of the variable clutch mechanism 100 comprises a generally disk-shaped member adapted for axial displacement along the shaft 22 and between the coils of the invention. 14, 16. The pressure wheel 102 includes a driven surface 130 and a drive surface 132 disposed on axially opposite faces of the pressure wheel 102. The drive surface 132 includes an annular surface which is substantially flat or flat. The driven surface 130 includes an annular surface of variable height H, where the height H of the driven surface 130 is defined as the distance between the driven surface 130 and the drive surface 132. In this configuration, it can also be said that the pressure wheel 102 of the present embodiment has a variable thickness T. In one embodiment, the driven surface 130 may comprise a cam surface of height H increasing from at least one valley 134 to at least one peak 136 to facilitate the operation of the variable clutch mechanism 100, as will be described below. In the embodiment described, the driven surface 130 includes first and second valleys 134a, 134b and first and second peaks 136a, 136b. The valleys 134a, 134b are disposed approximately 180 degrees apart from each other and in this configuration the first valley 134a is at the front of FIGS. 3A-3C, while the second valley 134a is at the front of FIGS. valley 134b is positioned behind the shaft 22. The crests 136a, 136b are also disposed at approximately one hundred and eighty degrees (180 "from each other, the first ridge 136a being positioned at the top of the pressure wheel 102 3A-3C Further relative angular positions between valleys 134a and 134b and crests 136a and 136b are also possible, for example, valleys 134 and crests 136 may be disposed at approximately one hundred twenty degrees (120 °), ninety degrees (90 °), sixty degrees (60 °), or forty-five degrees (45 ° to one another.) In some embodiments, the driven surface 130 can have a generally inclination angle nstant between the valleys 134a, 134b and the ridges 136a, 136b. In other embodiments, the angle of inclination between the valleys 134a, 134b and the ridges 136a, 136b may vary. For example, Figure 8 illustrates an embodiment of the driven surface 130 of the pressure wheel 102 having an inclination angle varying between the valleys 134a, 134b and the crests 136a, 136b. Similar to FIGS. 3A-3C, the valleys 134a, 134b of the driven surface 130 shown in FIG. 8 are disposed approximately one hundred and eighty degrees (180 °) from one another and in this configuration, the first valley 134a is in the foreground of Figure 8, while the second valley 134b is hidden and is not visible in Figure 8. The peaks 136a, 136b are also arranged at approximately one hundred and four twenty degrees (180 °) from each other, with the first ridge 136a positioned to the right and the second ridge 136b positioned to the left, relative to the orientation of Figure 8. The driven surface 130 of the The embodiment illustrated in FIG. 8 comprises a cam profile with a pressure angle that varies between a starting angle α1, located near the valley 134, and an ending angle a2, located near the peak 136. In FIG. a mode of realization the starting angle α1 is greater than the ending angle α2, and the driven surface 130 comprises a generally regular progressive transition between the starting angle α1 and the ending angle α2. For example, in one embodiment, the starting angle α1 may be between approximately 10.5 ° and approximately 16 °, between approximately 11.5 ° and approximately 15 °, and / or between approximately 12 ° and approximately 14 ° relative to a plane parallel to the driving surface 132 of the pressure wheel 102. For example, the starting angle α1 may be about 10.5 °, about 11.3 °, about 12.3 °, about 13.3 °, about 14.3 °, about 15.3 ° or about 16 ° to the plane parallel to the driving surface 132 of the pressure wheel 102. The end angle a2 can be between approximately 7.0 ° and approximately 12.5 °, between approximately 8 ° and approximately 11.5 °, and / or between approximately 9 ° and approximately 10.5 °, relative to a plane parallel to the driving surface 132 of the pressure wheel 102. For example, the end angle a2 may be about 7.0 °, about 7.8 °, about 8.8 °, about at 9.8 °, about 10.8 °, about 11.8 °, or about 12.5 °, with respect to a plane parallel to the driving surface 132 of the pressure wheel 102. Preferably, the surface driven 130 is configured to have a cam profile with a decreasing pressure angle which provides a substantially homogeneous clutching or pulling force as the bumps 115 pass valleys 134a, 134b at the crests 136a, 136b during any the life of the product (i.e., while the tape is dispensed from the product) as described herein. In various embodiments, the starting angle α1 may be about 10.5 ° and the end angle may be about 7.0 °, the starting angle α1 may be about 11.3 ° and the end angle may be about 7.8 °, the starting angle α1 may be about 12.3 ° and the end angle may be about 8.8 ° the starting angle α1 may be about 13.3 ° and the end angle may be about 9.8 °, the starting angle α1 may be about 14.3 °, and the end angle may be about 10.8 °, the starting angle α1 may be about 15.3 ° and the end angle may be about 11.8 °, and the angle of starting al can be about 16 ° and the end angle can be about 12.5 °. The pressure wheel 102 is disposed between the supply and receiving coils 14, 16 so that the shaft 22 passes through the opening 128 into the pressure wheel 102. In this configuration, the pressure wheel 102 is disposed coaxially with the supply and receiving coils 14, 16. In addition, in the present embodiment, the pressure wheel 102 is disposed within the cylindrical recess 112 of the supply reel 14 so that the driven surface 130 is slidably engaged by the protrusion 114 and in contact with the protrusion 114. It is not necessary to position the pressure wheel 102 in the recess 112 of the supply reel 14, but this is advantageous for obtaining a compact assembly and for reducing the overall dimensions of the clutch mechanism 100. This reduction in size can create a smaller, more aesthetically pleasing, correction tape dispenser 10, and functionally in line with expectations. The friction element 104 of the present embodiment generally comprises an O-ring 138 or gasket disposed around the shaft 22 between the pressure wheel 102 and the receiving coil 16. The O-ring comprises silicone or a material elastomer such as rubber. Alternatively, an O-ring or washer made of foam material may be used. More specifically, the O-ring 138 is partially disposed within the annular recess 123 formed in the inner surface 116 of the receiving coil 16 so that one side of the O-ring disposed opposite the The receiving coil 16 may be slidably engaged with the drive surface 132 of the pressure wheel 102. Although the friction element 104 of the present embodiment has been described as including the O-ring 138 alternative embodiments may include friction elements that may include other friction generating members, such as clutch plates / disks, flat rubber washers, viscous fluids, and the like. The annular recess 123 in the receiving coil 16 helps maintain the position of the O-ring 138 relative to the other components and also facilitates a reduction in the overall size of the assembly, which can be beneficial as it has been. discussed above. In some embodiments, the O-ring 138 may be fixable within the annular recess 123 with an adhesive or friction fit, for example. Similarly, the O-ring 138 may be injection molded with the receiving coil using a two-phase injection molding process and an elastomeric material to provide the O-ring structure. The ring ring 138 may have a circular cross-section, as shown, or it may have a square, octagonal or generally any other shape. In addition, the O-ring 138 may be made of an elastomeric material such as rubber, any other compressible elastic material, or generally any other material or combination of materials capable of serve the principles of this description. Figures 3A-3C show the variable clutch mechanism 100 in various operating states. Figure 3A shows the mechanism 100 in a state of rest. Fig. 3B shows the mechanism 100 in an initial operating state, i.e. a state in which the supply coil 14 comprises a relatively large supply of correction strip tape 20. Fig. 3C shows the mechanism 100 in a final operating state, i.e. a state in which the supply coil 14 comprises a substantially reduced supply of correction tape tape 20. The operation of the variable clutch mechanism 100 will be described. hereinafter with reference to Figures 1, 2 and 3A-3C. In the idle state shown in Fig. 3A, the correction tape dispenser 10 is not in use, and therefore no force F is applied to extract the correction tape strip 20 from the feed reel 14. The supply and reception coils 14, 16 are not subject to torque and the system is at rest. In this state, the bumps 115a and 115b of the supply reel 14 are respectively positioned in the valleys 134a, 134b of the pressure wheel 102. In this configuration, the annular ring 138 causes the pressure wheel 102 to take its place. position farthest to the left relative to the orientation of Figures 3A-3C, against the bumps 115a, 115b. Furthermore, in this state, the ring ring 138 undergoes very little, if any, compression, but it remains in frictional engagement with the driven surface 132 of the pressure wheel 102, which maintains the rotational position of the When a user begins to use the correction tape dispenser 10, as described above with reference to FIGS. 1 and 2, the user applies a pulling force F to extract the feed. As shown in FIG. 1, for example, the traction force F applied by the user generates a torque t on the supply reel 14 (which is the product of the tensile force F multiplied by the radius R of the supply of the correction strip ribbon 20), as shown in FIG. 1. In FIGS. 3A and 3B, the supply reel 14 contains a quantity of ribbon correction strip 20 having a radius R1, which is drawn by the user of the supply reel 14. As such, the user-supplied pulling force F initially causes rotation of the supply reel 14 relative to the pressure wheel 102 to the position shown in Figure 3B. Thus, the supply reel 14 rotates relative to the pressure wheel 102 so as to move the first bump 115a downwardly with respect to the orientation of Fig. 3A, and the second bump 115b upwardly with respect to the orientation of Figure 3A (where it was previously concealed as described above). As the feed spool 14 rotates, the friction between the driving surface 132 of the pressure wheel 102 and the friction element 104 maintains the rotational position of the pressure wheel 102 as far as it will go. the bumps 115a, 115b carried by the supply spool 14 transmit sufficient torque to the driven surface 130 to cause rotation of the pressure wheel 102. Thus, when the supply spool 14 and the bumps 115a 115b begin to rotate, the pressure wheel 102 and its driven surface 130 remain substantially fixed due to the friction generated between the friction element 104 and the drive surface 132. As such, the bumps 115a, 115b rotate. relative to the driven surface 130 of the pressure wheel 102 and begin to climb respectively to the crests 136a, 136b. When the bumps 115a, 115b rise towards the peaks 136a, 136b, the bumps 115a, 115b simultaneously move the pressure wheel 102 axially to the right, with respect to the orientation of FIGS. 3A-3C, and away from the supply reel 14 because the supply reel 14 is fixed so as to prevent axial displacement to the left beyond the latch 126 of the sleeve 120 of the receiving reel 16. When this occurs, the surface of drive 132 of the pressure wheel 102 axially compresses the O-ring 138 against the receiving coil 16. This increases the amount of friction generated between the O-ring 138 and the pressure wheel 102, and also the magnitude of a axial force applied to the pressure wheel 102 through the compressed O-ring 138, allowing at least a portion of the torque i generated on the supply reel 14 to be transferred to the receiving reel 16 via of the wheel of This causes the receiver coil 16 to rotate, in turn, in the same direction as the supply coil 14 to collect the carrier tape 20a used, as described above with reference to FIGS. 2. The relative displacement in rotation of the receiving reel 16 with respect to the supply reel 14 and the pressure wheel 102 nevertheless depends on the amount of friction generated by the variable clutch mechanism 100. This can be illustrated with reference to Figure 3C. Fig. 3C shows the correction tape dispenser 10 in a reduced supply state of the correction tape strip 20. Specifically, feeding the correction tape strip 20 to the feed reel 14 of Fig. 3C has a radius R2 substantially smaller than the radius R1 shown in Figures 3A and 3B. As a result, when a user applies the same amount of pulling force F to extract the correction tape strip 20 from the feed reel 14, the torque T generated on the feed reel 14, which is the product of the force F multiplied by the radius R2 is much smaller than the torque i generated on the supply reel 14 of FIGS. 3A and 3B. This lower torque rotates the supply spool 14 a smaller distance from the pressure wheel 102 because the slope of the driven surface 130 between the valleys 134a, 134b and the ridges 136a, 136b is more easily resisted. at the lower torque, which prevents the bumps 115a, 115b from mounting the slopes of the driven surface 130 as far as the peaks 136a, 136b. Because the bumps 115a, 115b rise a smaller distance to the peaks 136a, 136b, the pressure wheel 102 moves a smaller distance away from the feed reel 14 and compresses the ring toric 138 to a lesser extent. The extent to which the O-ring 138 is compressed in FIG. 3C generates less friction against the drive surface 132 of the pressure wheel 102 than the O-ring of FIG. 3B. This reduced friction allows the supply reel 14 to "slide" or "slip" relative to the receiving reel 16 when the user applies the pulling force F, thereby transferring a smaller torque t of the reel. in this configuration, in FIG. 3C, the receiving coil 16 rotates at a relative speed which is lower than the relative speed at which the supply reel 14 rotates, which ensures that the receiving reel 16 collects the carrier tape 20a used substantially at the same relative speed as that at which the supply reel 14 distributes the correction tape tape 20. In view of the above, it must be realized that the clutch mechanism 100 shown in Figures 3A-3C is also arranged and configured to automatically vary the relative speed of rotation of the receiving coil 16 according to the quantization a strip of correction strip tape 20 stored on the supply spool 14. Thus, when the correction strip dispenser 10 is relatively new and the supply spool 14 comprises a relatively large supply of correction strip tape 20, the supply and receiving coils 14, 16 rotate at a generally common relative speed because the pressure wheel 102 applies a relatively large compressive force to the O-ring 138, which generates a relatively large amount of friction between the This large amount of friction may, in some cases, essentially fix the supply and receiving coils 14, 16 to each other. As the feed of the correction tape 20 to the feed reel 14 decreases, the feed radius of the correction tape 20 decreases and the radius of the carrier tape 20a collected on the receiving coil 16 increases. Therefore, to ensure that the relative speed at which the correction tape 20 is pulled from the feed reel 14 is substantially the same as the relative speed at which the carrier tape 20a is collected by the receiving reel 16, the relative rotational speed of the supply reel 14 must increase or the relative speed of rotation of the receiving reel 16 must decrease. In the embodiment described, the relative speed of rotation of the receiving coil 16 is decreased by reducing the compressive force applied by the pressure wheel 102 to the O-ring 138, which reduces the amount of friction between the coils. This relatively small amount of friction allows the supply reel 14 and the pressure wheel 102 to slide relative to the receiving reel 16, allowing the receiving reel 16, the carrier tape used at the same relative speed as the one at which the correction band is removed from the supply reel 14. This variable clutch mechanism 100 thus automatically adjusts the relative speed at which the receiving reel 16 rotates relative to the supply reel 14 to ensure that the correction strip tape 20 is regularly transferred from the supply reel 14 so that the carrier tape 20a is collected by the receiving coil 16 without generating a too large or too small tension in the correction tape strip 20 and / or in the carrier tape 20a, which avoids operational irregularities such as tearing and / or looping. Although the friction element 104 of the variable clutch mechanism embodiment 100 shown in Figs. 3A-3C includes an O-ring 138 which is separate and distinct from the other system components, modified embodiments and / or alternatively may be constructed differently. For example, FIG. 4 shows a modified embodiment of the variable clutch mechanism 100 of FIGS. 3A-3C, in which the friction element 104 is formed integrally, that is to say of a single The variable clutch mechanism 100 of Fig. 4 is otherwise identical to the variable clutch mechanism 100 of Figs. 3A-3C in terms of structure and function. The friction element 104 of FIG. 4 is formed of a resilient and deformable annular ring projecting from the driving surface 132 of the pressure wheel 102 to effect the operation of the variable clutch mechanism 100, as has been described in FIG. has been described above. In the described embodiment, the integral friction element 104 comprises a generally semicircular cross-section, but other cross-sectional shapes are also within the scope of this disclosure. The friction element 104 and the pressure wheel 102 of FIG. 4 can be formed using a coextrusion process, a comoulage process or any other manufacturing process, or any combination of processes. The process of forming the pressure wheel 102 and the friction element 104 is generally simultaneously in the same process or in different processes at different times. Although the variable clutch mechanism 100 heretofore described utilizes a resilient and deformable friction member 104 to perform its function, other embodiments may be constructed to utilize more rigid friction generating components. Figure 5 shows an alternative variable clutch mechanism 200 which is constructed in accordance with the principles of the present description and which has a friction element 204 including a clutch plate, as will be described hereinafter. Like the variable clutch mechanism 100 described above, and for the sake of explanation, the clutch mechanism 200 of FIG. 5 is described as a component of the correction tape dispenser 10 shown in FIGS. The variable clutch mechanism 200 thus comprises the supply and receiving coils 14, 16 of the correction strip dispenser 10, a pressure wheel 202 and the friction element 204.

In the embodiment described, the feed reel 14 has an inner surface 206, an outer surface 208, a cylindrical boss 210 extending from the inner surface 206, a through bore 212, and at least one protuberance 214 extending radially outwardly from the boss 210. The receiving coil 16 includes an inner surface 216, an outer surface 218, and an opening 220. As illustrated and mentioned above, the supply and receiving coils 14, 16 are arranged coaxially for rotational movement on the shaft 22 of the correction tape dispenser 10, and they generally comprise disks or disc-shaped members. More specifically, the shaft 22 of the correction tape dispenser 10 extends through the through bore 212 of the feed spool 14 and the opening 220 of the take-up spool 16 to rotatably support these components. The feed reel 14 retains a stock of the correction tape 20, and the reel 16 retains a used stock of the carrier tape 20a. In the present embodiment, the at least one protrusion 214 on the boss 210 of the feed reel 14 includes first and second generally cylindrical pins 215a, 215b, only the first of which is visible in FIG. because the pins 215a, 215b are disposed approximately one hundred and eighty degrees (180 "apart.) The visible peg 215a extends generally perpendicular to the plane through which the cross section of FIG. The pegs 215a, 215b are provided to participate in the operation of the clutch mechanism 200, as will be described hereinafter. In alternative embodiments, the feed reel 14 may comprise more or fewer than two pins 215a, 215b and the pins 215a, 215b may be arranged in a shape other than a generally cylindrical shape. Alternatively, the relative angular positions between pegs 215 are also possible. For example, pegs 215 may be disposed approximately one hundred twenty degrees (120 degrees), ninety degrees (90 degrees, sixty degrees (60 degrees), or forty-five degrees (45 degrees) relative to one another. The pressure wheel 202 of the present embodiment of the variable clutch mechanism 200 comprises a generally disk-shaped member adapted for axial displacement along the shaft 22 and between the supply and the receiving coils. 14, 16. The pressure wheel 202 includes a driven surface 230 and a drive surface 232 disposed on axially opposed faces of the pressure wheel 202. The drive surface 232 includes an annular surface that is substantially flat or flat The driven surface 230 comprises an annular surface of variable height H, where the height H of the driven surface 230 is defined as the distance between the driven surface 230 and the drive surface 232. In this In the configuration, it can be said that the pressure wheel 202 of the present embodiment has a variable thickness T.

In one embodiment, the driven surface 230 may include a cam surface of increasing height H from at least one valley 234 to at least one ridge 236 to facilitate operation of the variable clutch mechanism 200. In the embodiment described, the driven surface 230 comprises two valleys 234a, 234b and two peaks 236a, 2361), as the driven surface 130 of the pressure wheel 102 of the variable clutch mechanism embodiment 100 described above with reference to the figures 3A-3C. Of course, more or less than two valleys 234 and two peaks 236 may be employed. For example, the driven surface 230 may alternatively comprise one, three, four, five, six, seven, eight or more valleys 234 and ridges 236. As illustrated, the pressure wheel 202 of FIG. between the supply and receiving coils 14, 16 so that the shaft 22 passes through the opening 228 in the pressure wheel 202. In this configuration, the pressure wheel 202 is arranged coaxially with the supply coils and In addition, as shown in FIG. 5, the present embodiment of the variable clutch mechanism 200 includes a biasing member 205 disposed between the feed reel 14 and the driven surface 230 of the machine. pressure wheel 202 for constraining the pressure wheel 202 to the receiving coil 16. In some embodiments, the constraining member 205 may comprise a spring such as, for example, a Belleville spring, which is a spring element. e elastic cup-shaped.

The friction element 204 of the embodiment of Figure 5 comprises a clutch plate 238, as mentioned above. The clutch plate 238 is carried by the drive surface 232 of the pressure wheel 202 and is therefore generally an annular flat plate. The clutch plate 238 may consist of generally any friction generating material, such as ceramic, metal, plastic, silica, etc. or generally any other material or combination of materials capable of serving the principles of the present disclosure. In use, the clutch mechanism 200 of Figure 5 operates substantially like the clutch mechanism 100 described above with reference to Figures 3A-3C. For example, when a user applies a force F to extract the correction tape strip 20 from the feed reel 14, the pins 215a, 215b rotate with respect to the pressure wheel 202 so that they rise at least partially. the slopes of the driven surface 230 of the valleys 234a, 2341) to the ridges 236. As the pins 215a, 215b mount the inclined surfaces, the pins 215a, 215b simultaneously push the pressure wheel 202 towards the spool. receiving 16 so that the clutch plate 238 is constrained against the inner surface 216 thereof to generate friction. In some embodiments, the inner surface 216 of the take-up reel 16 may include a clutch face 217, as shown in FIG. 5, for frictional engagement with the clutch plate 238. clutch face 217 may extend away from inner surface 216 of receiving spool 16 and may be of generally annular shape to correspond to the shape of clutch plate 238. The distance from which pegs 215a, 215b move the pressure wheel 202 and thus the amount of axial friction generated by the clutch plate 238 depend on the amount of torque i generated on the supply reel 14 during operation.

Although the variable clutch mechanism 200 of FIG. 5 is described as comprising a single clutch plate 238 operatively engaging the receiving coil 16 through the operation of a pressure wheel 202 With cams, variant variable clutch mechanisms constructed according to the principles of the present description may comprise two or more clutch plates for example, and alternative mechanisms for varying the magnitude of the friction thus generated. Such a mechanism, to vary the magnitude of the friction, is described, alternatively, with reference to FIG. 6. FIG. 6 represents another variant variable clutch mechanism 300 constructed according to the principles of the present description, and which comprises a friction element 304 comprising an inner clutch plate 338a and an outer clutch plate 338b. Like the variable clutch mechanisms 100, 200 described above, and for the sake of explanation, the clutch mechanism 300 of FIG. 6 is described as being a component of the correction strip dispenser 10 shown in FIGS. and 2. The variable clutch mechanism 300 thus comprises the supply and receiving coils 14, 16 of the correction strip dispenser 10, a pressure wheel 302 and the friction element 304.

In the embodiment of Fig. 6, the feed reel 14 includes an inner surface 306, an outer surface 308, and an opening 310 including at least one protuberance 312. In the present embodiment, the at least one protrusion 312 of the supply reel 14 comprises a plurality of internal threads 313. The receiving reel 16 includes an inner surface 316, an outer surface 318, a cylindrical boss 314 extending from the inner surface 316, and a through bore 320 extending through the boss 314. As illustrated and mentioned above, the supply and receiving coils 14, 16 are arranged for rotational movement on the shaft 22 of the correction tape dispenser 10, and they comprise usually discs or disc-shaped members. More specifically, the shaft 22 of the correction tape dispenser 10 extends through the through bore 320 of the receiving coil 16 and the opening 310 of the feed reel 14 and supports the components. The feed reel 14 retains a stock of the correction tape 20, and the reel 16 retains a used stock of the carrier tape 20a. The pressure wheel 302 of the present embodiment of the variable clutch mechanism 300 comprises a generally disk-shaped member adapted for axial movement along the shaft 22 and between the supply and receiving coils 14, 16 The pressure wheel 302 includes a driven surface 330 and a drive surface 332. In the present embodiment, the driven surface 330 includes a plurality of external threads 333 disposed on the outer radial surface of the pressure wheel 302 and in engagement with the plurality of internal threads 312 of the feed reel 14. The drive surface 332 includes an annular surface which is substantially flat or flat and which can, as shown, protrude outwardly to from the rest of the pressure wheel 302 in the axial direction to the receiving reel 16. As illustrated, the pressure wheel 302 of FIG. between the supply and receiving coils 14, 16 so that the shaft 22 passes through the through bore 320 of the cylindrical boss 314 of the receiving coil 16. The pressure wheel 302 further comprises an opening 328 which is disposed in the cylindrical boss 314 of the receiving coil 16. In this configuration, the pressure wheel 302 is arranged coaxially with the supply and receiving coils 14, 16. In addition, as shown in FIG. This embodiment of the variable clutch mechanism 300 comprises a constraining member 305 disposed between a retaining clip 319, which is attached to one end of the cylindrical boss 314, and the pressing wheel 302 to constrain the pressure wheel 302 to In some embodiments, the biasing member 305 may comprise a spring such as a Belleville spring. As mentioned above, the friction element 304 of the embodiment of Fig. 6 includes the inner and outer clutch plates 338a, 338b. The inner clutch plate 338a is a generally flat, annular plate which is carried by an annular protuberance 325 extending from the pressure wheel 302 and defining the driving surface 332. Under the effect of the pressure constraint 305, the inner clutch plate 338a is adapted to generate an axial friction between the pressure wheel 302 and the receiving coil 16. Therefore, the inner clutch plate 338a may be constituted of generally n ' any material generating friction, such as ceramic, metal, plastic, silica, etc. or generally any other material or combination of materials capable of serving the principles of the present disclosure. The outer clutch plate 3381) is also a generally flat annular plate, but is carried by an annular protrusion 327 extending from the inner surface 306 of the supply reel 14. The outer clutch plate 3381 ) is adapted to generate varying degrees of axial friction between the supply and receiving coils 14, 16 to participate in the operation of the variable clutch mechanism 300, as will be described hereinafter. Therefore, the outer clutch plate 3381) is generally made of a flexible, deformable and / or elastic material alone or in combination with one or more friction generating materials as described herein. During operation of the variable clutch mechanism 300 of Fig. 6, a user applies a force F to extract the correction tape strip 20 from the feed reel 14 as described above with reference to Figs. and 2. This force F causes the internal threads 312 of the supply reel 14 to slide relative to the external threads 313 of the pressure wheel 302, which moves the supply reel 14 in the axial direction to the reel This causes the outer clutch plate 3381 carried by the feed reel 14 to puncture with the take-up spool 16 and compress against it. More specifically, the outer clutch plate 338b is forcibly engaging an outer annular protrusion 317b extending from the inner surface 316 of the receiving coil 16. The amount of axial friction generated between the supply coils and 14, 16 by the outer clutch plate 3381) depends on the degree of axial compression of the outer clutch plate 338b. In addition, the degree of compression of the outer clutch plate 3381) depends on the magnitude of the torque i generated on the supply reel 14 by the user, as described above with respect to the variable clutch mechanisms 100, 200 shown in FIGS. 3A-3C, 4 and 5. It should be appreciated that the outer clutch plate 3381) of the present embodiment is arranged and configured to generate a variable amount of friction between the supply and receiving coils 14, 16, which, in turn, ensures the correct operation of the correction tape dispenser 10. In addition, in the present embodiment, the compression of the printing plate external clutch 3381) imparts a return force to the system, which automatically returns the supply reel 14 to its original position when the user stops applying the correction band 20b. Although the variable clutch mechanisms 100, 200, 300 described so far operate by the implementation of friction elements 104, 204, 304 comprising conventional O-rings or clutch plates, alternatively, Other mechanisms for varying the magnitude of friction between the supply and receiving coils 14, 16 are intended to be within the scope of this disclosure. For example, FIG. 7 shows another variant variable clutch mechanism 400 constructed according to the principles of the present description, and which has a friction element 404 comprising a compatible hub 438. Like the variable clutch mechanisms 100, 200 300, described above, and for the sake of explanation, the clutch mechanism 400 of FIG. 7 is described as being a component of the correction tape dispenser 10 shown in FIGS. 1 and 2. The clutch mechanism variable 400 thus comprises the supply and receiving coils 14, 16 of the correction band dispenser 10, a pressure wheel 402 and the friction element 404. In the embodiment of FIG. feed 14 includes an inner surface 406, an outer surface 408, and an opening 410 including at least one protrusion 412. In the present embodiment, the at least one protrusion 412 comprises a plummet. The receiving coil 16 comprises an inner surface 416, an outer surface 418, a cylindrical boss 414 extending from the inner surface 416, a through bore 420 extending through the boss 414, and a cylindrical flange 417 spaced radially outwardly from the cylindrical boss 414. As illustrated and mentioned above, the supply and receiving coils 14, 16 are arranged for rotational movement on the shaft 22 of the belt distributor. correction 10, and they generally comprise disks or disc-shaped members. More specifically, the shaft 22 of the correction tape dispenser 10 extends through the through bore 420 of the cylindrical boss 414 of the receiving coil 16 and the opening 410 of the feed reel 14 to support these components. rotatively. Further, as illustrated, the supply and receiving coils 14,16 of the present embodiment are fixed against axial displacement relative to one another by means of tab-type flanges. and cylindrical grooves 319a, 319b correspondingly mating, extending from the inner surfaces respectively of the supply and receiving coils 14, 16. The supply reel 14 retains a stock of the correction tape 20, and the receiving reel 16 retains a used stock of the carrier tape 20a. The pressure wheel 402 of the present embodiment of the variable clutch mechanism 400 is adapted for axial displacement along the shaft 22 and with respect to the supply and receiving coils 14, 16. The pressure wheel 402 comprises a driving portion 402a and a clutch portion 402b. The driving portion 402a comprises a generally annular disc-shaped member defining a driven surface 430 having a plurality of outer threads 433. The outer threads 433 are disposed on the radially outer surface of the pressing wheel 402 and meshing with the plurality of inner threads 412 of the supply spool 14. The clutch portion 402b of the pressure wheel 402 comprises a generally hollow cylindrical member serving as a friction member 404 and disposed between the cylindrical boss 414 and the cylindrical collar 417 of the take-up spool 16. The clutch portion 402b further includes a round nose outer surface 403 slidably engaged with an inner cylindrical surface 417a of the cylindrical flange 417 to generate varying amounts of friction between the wheel. 402 and the receiving coil 16 during operation of the clutch mechanism var For example, during operation of the variable clutch mechanism 400 of Fig. 7, a user applies a force F to extract the correction tape strip 20 from the feed reel 14 as described above. The force F causes the internal threads 413 of the feed reel 14 to slide relative to the outer flaps 433 of the pressure wheel 402, which moves the pressure wheel 402 in the direction of axial to the take-up reel 16. This causes the round nose surface 403 of the clutch portion 402b to frictionally engage the inner cylindrical surface 417a of the cylindrical collar 417 of the take-up spool 16. The amount of friction generated between the round nose surface 403 and the cylindrical flange 417 depends on the magnitude of the torque i generated on the supply reel 14 by the user, as has been described. above with respect to the variable clutch mechanisms 100, 200, 300 shown in Figures 3A-3C, 4, 5 and 6. It should be appreciated that the clutch portion 402b of the pressure wheel 402 of the present embodiment is arranged and configured to generate a variable amount of friction between the supply and the receiving coils 14, 16, which, in turn, ensures the correct operation of the correction tape dispenser 10. furthermore, in some embodiments, the clutch portion 402b of the pressure wheel 402 may be made of a resilient, deformable material such that the round nose surface 403 is at least partially compressed by being constrained against the surface cylindrical collar 417a of the cylindrical collar 417 of the receiving coil 16. In this configuration, the elasticity of the clutch portion 402b can naturally force the pressure wheel 402 to return to the position shown in FIG. 7 when the user stops applying the correction band 20b. In view of the foregoing, each of the variable clutch mechanisms 100, 200, 300, 400 described herein is capable of optimizing the application of the correction band 20b carried on a supply of the correction tape strip 20 by ensuring that the relative speed at which the carrier tape 20a used is collected on the receiving roll 16 is substantially equal to the relative speed at which the correction tape 20 is extracted from the feed reel 14 regardless of the magnitude of the force F applied to the correction tape 20 by the user. This is accomplished by varying a frictional force between the supply and receiving coils 14, 16 generated by a friction element 104, 204, 304, 404. Thus, when the supply of the correction tape 20 is relatively large, it may be advantageous for the supply and receiving coils 14, 16 to rotate substantially at the same relative speed because the radius of the correction tape feed 20 may be relatively similar to the radius of the carrier tape 20a used collected on the receiving coil 16. In addition, when the supply of tape correction tape 20 is small, it may be advantageous that the supply coil 14 rotates at a relative speed greater than that at which the coil The reception runner 16 rotates because the supply radius of the correction strip tape 20 may be smaller than the radius of the carrier tape 20a collected on the receiving roll 16. Thus, each Previous embodiments of the variable clutch mechanism 100, 200, 300, 400 are capable of providing similar advantages and advantages. Although this description expressly describes various embodiments of variable clutch mechanisms, the invention is not intended to be limited by the features described herein. Instead, the invention must be defined by the spirit and scope of the appended claims, including all their equivalences.

Claims (9)

REVENDICATIONS1. A clutch mechanism (100; 200; 300; 400) comprising: a first rotation disk defining at least one protuberance (114; 214; 312; 412); a second rotation disk disposed coaxially with the first rotation disk; a pressure wheel (102; 202; 302; 402) disposed coaxially with and between the first and second rotation discs, the pressure wheel (102; 202; 302; 402) being operatively engaged by the at least one protuberance (114; 214; 312; 412), the at least one protuberance (114) being movable between at least a first rotational position and a second rotational position with respect to the pressure wheel (102; 202; 302; 402); a friction element (104; 204; 304; 404) disposed between the pressure wheel (102; 202; 302; 402) and the second rotation disk so that the friction element (104; 204; 304; 404); ) generates a first friction force between the pressure wheel (102; 202; 302; 402) and the second rotation disk when the at least one protrusion (114; 214; 312; 412) is in the first position of rotation and a second frictional force between the pressure wheel (102; 202; 302; 402) and the second rotation disk when the at least one protrusion (114; 214; 312; 412) is in the second position of rotation. The clutch mechanism (100; 200; 300; 400) according to claim 1, wherein the pressure wheel (102; 202; 302; 402) and the friction element (104; 204; 304; 404). are separate components. The clutch mechanism (100; 200; 300; 400) according to any of the preceding claims, wherein the friction element (104; 204; 304; 404) comprises an O-ring (138). The clutch mechanism (100; 200; 300; 400) according to any one of the preceding claims, wherein the friction element (104) comprises a clutch plate (238; 338a; 338b). The clutch mechanism (100; 200; 300; 400) according to any one of the preceding claims, wherein the friction element (104; 204; 304; 404) is integrally formed with the pressure wheel. (102; 202; 302; 402). The clutch mechanism (100; 200; 300; 400) according to any one of the preceding claims, wherein the friction element (104; 204; 304; 404) comprises an annular resilient protuberance extending from the pressure wheel (102; 202; 302; 402). The clutch mechanism (100; 200; 300; 400) according to any one of the preceding claims, wherein the pressure wheel (102; 202; 302; 402) comprises a cam surface facing the first disc of and the at least one protrusion (114; 214; 312; 412) carried by the first rotational disk comprises a boss (115a; 115b) slidably engaging the cam surface. The clutch mechanism (100; 200; 300; 400) according to any one of the preceding claims, wherein the at least one protrusion (114; 214,312; 412) carried by the first rotation disk comprises a a plurality of threads (313) engaging the pressure wheel (102; 202; 302; 402), The clutch mechanism (100; 200; 300; 400) according to any one of the preceding claims, further comprising a recess (112) formed in the first rotation disk, wherein at least a portion of the wheel pressure (102; 202; 302; 402) is disposed in the recess (112). A tape dispenser (10), comprising: a housing (12); an application head (18) carried by the housing (12); a supply reel (14) supported in the housing (12) and adapted to carry a correction web supply (20b) adapted to be applied to a support by the application head (18), the supply reel (14) smoothing at least one protuberance (114; 214; 312; 412); a receiving coil (16) supported in the housing (12) and disposed coaxially with the supply reel (14), the receiving reel (16) for collecting a carrier tape (20a) after applying the web correction (20b) on the support; a pressure wheel (102; 202; 302; 402) disposed coaxially with and between the supply and receiving coils (14,16), the pressure wheel (102; 202; 302; 402) being engaged; operatively by the at least one protuberance (114; 214; 312; 412), the at least one protuberance (114; 214; 312; 412) being movable between at least a first rotational position and a second rotational position; rotation relative to the pressure wheel (102; 202; 302; 402); and a friction element (104; 204; 304; 404) disposed between the pressure wheel (102; 202; 302; 402) and the receiving coil (16) so that the friction element (104; 204; 304; 404) generates a first friction force between the supply and the receiving coils (14, 16) when the at least one protuberance (114) is at the first rotational position and a second friction force between the supply and receiving coils (14, 16) when the at least one protuberance (114; 214; 312; 412) is in the second rotational position. The belt dispenser (10) of claim 10, wherein the pressure wheel (102; 202; 302; 402) and the friction element (104; 204; 304; 404) are separate components. The tape dispenser (10) of claim 10 or 11, wherein the friction member (104; 204; 304; 404) comprises an O-ring (138). The belt dispenser (10) according to any one of claims 10 to 12, wherein the friction element (104; 204; 304; 404) comprises a clutch plate (238; 338a; 338b). The tape dispenser (10) according to any one of claims 10 to 13, wherein the friction element (104; 204; 304; 404) is integrally formed with the pressure wheel (102; 202; 302; 402). The tape dispenser (10) according to any one of claims 10 to 14, wherein the friction element (104; 204; 304; 404) comprises an annular resilient protrusion extending from the pressure wheel (102). 202, 302, 402). The tape dispenser (10) according to any one of claims 10 to 15, wherein the pressure wheel (102; 202; 302; 402) comprises a cam surface facing the feed reel (14). and the at least one protrusion (114; 214; 312,412) carried by the feed reel (14) comprises a boss slidably engaging the cam surface. The tape dispenser (10) according to any one of claims 10 to 16, wherein the at least one protrusion (114; 214; 312; 412) carried by the feed reel (14) comprises a plurality of threads (313) meshing with the pressure wheel (102; 202; 302; 402) .18. A tape dispenser (10) according to any one of claims 10 to 17, further comprising a recess (112) formed in the feed reel (14), wherein at least a portion of the pressure wheel (102; 202; 302; 402) is disposed in the recess (112). The tape dispenser (10) according to any one of claims 10 to 18, further comprising a shaft (22) carried by the housing (12) and rotatably supporting the feed reel (14), the receiving coil (16), and the pressing wheel (102; 202; 302; 402). A correction tape dispenser (10), comprising: a housing (12) carrying an applicator head (18) and a shaft (22); a feed spool (14) rotatably supported on the shaft (22) and defining a bump (115a; 115b); a take-up spool (16) rotatably supported on the shaft (22) adjacent to the feed spool (14); a carrier tape (20a) carrying a correction tape feed (20b), the carrier tape (20a) extending from the feed reel (14), around the application head (18), and up to at the receiving coil (16); a pressure wheel (102; 202; 302; 402) disposed on the shaft (22) between the supply and receiving coils (14,16), the pressure wheel (102; 202; 302; 402) defining a cam surface which is operatively engaged by the boss (115a; 115b), the supply spool (14) being movable relative to the pressure wheel (102) so that the boss (115a; 115b) ) can be displaced with respect to the cam surface between at least a first rotational position and a second rotational position; the pressure wheel (102; 202; 302; 402) being movable relative to the supply spool (14) between a first axial position when the boss (115a; 115b) is at the first rotational position and a second rotational position; axial position when the boss (115a; 115b) is in the second rotational position; and an O-ring (138) disposed between the pressure wheel (102; 202; 302; 402) and the receiving coil (16) so that the O-ring (138) occupies a first compression state and generates a first friction force between the supply and receiving coils (14, 16) when the boss (115a; 115b) is in the first rotational position and the pressure wheel (102; 202; 302; 402) is at the first rotational position; first axial position, and a second compression state generating a second friction force between the supply and receiving coils (14, 16) when the boss (115a; 115b) is at the second rotational position and the pressure (102; 202; 302; 402) is at the second axial position.